1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
4 */
5
6 #include <linux/fs_context.h>
7 #include <linux/fs_parser.h>
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/time.h>
11 #include <linux/mount.h>
12 #include <linux/cred.h>
13 #include <linux/statfs.h>
14 #include <linux/seq_file.h>
15 #include <linux/blkdev.h>
16 #include <linux/fs_struct.h>
17 #include <linux/iversion.h>
18 #include <linux/nls.h>
19 #include <linux/buffer_head.h>
20 #include <linux/magic.h>
21
22 #include "exfat_raw.h"
23 #include "exfat_fs.h"
24
25 static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET;
26 static struct kmem_cache *exfat_inode_cachep;
27
exfat_free_iocharset(struct exfat_sb_info * sbi)28 static void exfat_free_iocharset(struct exfat_sb_info *sbi)
29 {
30 if (sbi->options.iocharset != exfat_default_iocharset)
31 kfree(sbi->options.iocharset);
32 }
33
exfat_delayed_free(struct rcu_head * p)34 static void exfat_delayed_free(struct rcu_head *p)
35 {
36 struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu);
37
38 unload_nls(sbi->nls_io);
39 exfat_free_iocharset(sbi);
40 exfat_free_upcase_table(sbi);
41 kfree(sbi);
42 }
43
exfat_put_super(struct super_block * sb)44 static void exfat_put_super(struct super_block *sb)
45 {
46 struct exfat_sb_info *sbi = EXFAT_SB(sb);
47
48 mutex_lock(&sbi->s_lock);
49 exfat_free_bitmap(sbi);
50 brelse(sbi->boot_bh);
51 mutex_unlock(&sbi->s_lock);
52
53 call_rcu(&sbi->rcu, exfat_delayed_free);
54 }
55
exfat_sync_fs(struct super_block * sb,int wait)56 static int exfat_sync_fs(struct super_block *sb, int wait)
57 {
58 struct exfat_sb_info *sbi = EXFAT_SB(sb);
59 int err = 0;
60
61 if (!wait)
62 return 0;
63
64 /* If there are some dirty buffers in the bdev inode */
65 mutex_lock(&sbi->s_lock);
66 sync_blockdev(sb->s_bdev);
67 if (exfat_clear_volume_dirty(sb))
68 err = -EIO;
69 mutex_unlock(&sbi->s_lock);
70 return err;
71 }
72
exfat_statfs(struct dentry * dentry,struct kstatfs * buf)73 static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)
74 {
75 struct super_block *sb = dentry->d_sb;
76 struct exfat_sb_info *sbi = EXFAT_SB(sb);
77 unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev);
78
79 if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) {
80 mutex_lock(&sbi->s_lock);
81 if (exfat_count_used_clusters(sb, &sbi->used_clusters)) {
82 mutex_unlock(&sbi->s_lock);
83 return -EIO;
84 }
85 mutex_unlock(&sbi->s_lock);
86 }
87
88 buf->f_type = sb->s_magic;
89 buf->f_bsize = sbi->cluster_size;
90 buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */
91 buf->f_bfree = buf->f_blocks - sbi->used_clusters;
92 buf->f_bavail = buf->f_bfree;
93 buf->f_fsid = u64_to_fsid(id);
94 /* Unicode utf16 255 characters */
95 buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;
96 return 0;
97 }
98
exfat_set_vol_flags(struct super_block * sb,unsigned short new_flags)99 static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)
100 {
101 struct exfat_sb_info *sbi = EXFAT_SB(sb);
102 struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
103
104 /* retain persistent-flags */
105 new_flags |= sbi->vol_flags_persistent;
106
107 /* flags are not changed */
108 if (sbi->vol_flags == new_flags)
109 return 0;
110
111 sbi->vol_flags = new_flags;
112
113 /* skip updating volume dirty flag,
114 * if this volume has been mounted with read-only
115 */
116 if (sb_rdonly(sb))
117 return 0;
118
119 p_boot->vol_flags = cpu_to_le16(new_flags);
120
121 set_buffer_uptodate(sbi->boot_bh);
122 mark_buffer_dirty(sbi->boot_bh);
123
124 __sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH);
125
126 return 0;
127 }
128
exfat_set_volume_dirty(struct super_block * sb)129 int exfat_set_volume_dirty(struct super_block *sb)
130 {
131 struct exfat_sb_info *sbi = EXFAT_SB(sb);
132
133 return exfat_set_vol_flags(sb, sbi->vol_flags | VOLUME_DIRTY);
134 }
135
exfat_clear_volume_dirty(struct super_block * sb)136 int exfat_clear_volume_dirty(struct super_block *sb)
137 {
138 struct exfat_sb_info *sbi = EXFAT_SB(sb);
139
140 return exfat_set_vol_flags(sb, sbi->vol_flags & ~VOLUME_DIRTY);
141 }
142
exfat_show_options(struct seq_file * m,struct dentry * root)143 static int exfat_show_options(struct seq_file *m, struct dentry *root)
144 {
145 struct super_block *sb = root->d_sb;
146 struct exfat_sb_info *sbi = EXFAT_SB(sb);
147 struct exfat_mount_options *opts = &sbi->options;
148
149 /* Show partition info */
150 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
151 seq_printf(m, ",uid=%u",
152 from_kuid_munged(&init_user_ns, opts->fs_uid));
153 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
154 seq_printf(m, ",gid=%u",
155 from_kgid_munged(&init_user_ns, opts->fs_gid));
156 seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask);
157 if (opts->allow_utime)
158 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
159 if (opts->utf8)
160 seq_puts(m, ",iocharset=utf8");
161 else if (sbi->nls_io)
162 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
163 if (opts->errors == EXFAT_ERRORS_CONT)
164 seq_puts(m, ",errors=continue");
165 else if (opts->errors == EXFAT_ERRORS_PANIC)
166 seq_puts(m, ",errors=panic");
167 else
168 seq_puts(m, ",errors=remount-ro");
169 if (opts->discard)
170 seq_puts(m, ",discard");
171 if (opts->keep_last_dots)
172 seq_puts(m, ",keep_last_dots");
173 if (opts->sys_tz)
174 seq_puts(m, ",sys_tz");
175 else if (opts->time_offset)
176 seq_printf(m, ",time_offset=%d", opts->time_offset);
177 return 0;
178 }
179
exfat_alloc_inode(struct super_block * sb)180 static struct inode *exfat_alloc_inode(struct super_block *sb)
181 {
182 struct exfat_inode_info *ei;
183
184 ei = alloc_inode_sb(sb, exfat_inode_cachep, GFP_NOFS);
185 if (!ei)
186 return NULL;
187
188 init_rwsem(&ei->truncate_lock);
189 return &ei->vfs_inode;
190 }
191
exfat_free_inode(struct inode * inode)192 static void exfat_free_inode(struct inode *inode)
193 {
194 kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));
195 }
196
197 static const struct super_operations exfat_sops = {
198 .alloc_inode = exfat_alloc_inode,
199 .free_inode = exfat_free_inode,
200 .write_inode = exfat_write_inode,
201 .evict_inode = exfat_evict_inode,
202 .put_super = exfat_put_super,
203 .sync_fs = exfat_sync_fs,
204 .statfs = exfat_statfs,
205 .show_options = exfat_show_options,
206 };
207
208 enum {
209 Opt_uid,
210 Opt_gid,
211 Opt_umask,
212 Opt_dmask,
213 Opt_fmask,
214 Opt_allow_utime,
215 Opt_charset,
216 Opt_errors,
217 Opt_discard,
218 Opt_keep_last_dots,
219 Opt_sys_tz,
220 Opt_time_offset,
221
222 /* Deprecated options */
223 Opt_utf8,
224 Opt_debug,
225 Opt_namecase,
226 Opt_codepage,
227 };
228
229 static const struct constant_table exfat_param_enums[] = {
230 { "continue", EXFAT_ERRORS_CONT },
231 { "panic", EXFAT_ERRORS_PANIC },
232 { "remount-ro", EXFAT_ERRORS_RO },
233 {}
234 };
235
236 static const struct fs_parameter_spec exfat_parameters[] = {
237 fsparam_u32("uid", Opt_uid),
238 fsparam_u32("gid", Opt_gid),
239 fsparam_u32oct("umask", Opt_umask),
240 fsparam_u32oct("dmask", Opt_dmask),
241 fsparam_u32oct("fmask", Opt_fmask),
242 fsparam_u32oct("allow_utime", Opt_allow_utime),
243 fsparam_string("iocharset", Opt_charset),
244 fsparam_enum("errors", Opt_errors, exfat_param_enums),
245 fsparam_flag("discard", Opt_discard),
246 fsparam_flag("keep_last_dots", Opt_keep_last_dots),
247 fsparam_flag("sys_tz", Opt_sys_tz),
248 fsparam_s32("time_offset", Opt_time_offset),
249 __fsparam(NULL, "utf8", Opt_utf8, fs_param_deprecated,
250 NULL),
251 __fsparam(NULL, "debug", Opt_debug, fs_param_deprecated,
252 NULL),
253 __fsparam(fs_param_is_u32, "namecase", Opt_namecase,
254 fs_param_deprecated, NULL),
255 __fsparam(fs_param_is_u32, "codepage", Opt_codepage,
256 fs_param_deprecated, NULL),
257 {}
258 };
259
exfat_parse_param(struct fs_context * fc,struct fs_parameter * param)260 static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
261 {
262 struct exfat_sb_info *sbi = fc->s_fs_info;
263 struct exfat_mount_options *opts = &sbi->options;
264 struct fs_parse_result result;
265 int opt;
266
267 opt = fs_parse(fc, exfat_parameters, param, &result);
268 if (opt < 0)
269 return opt;
270
271 switch (opt) {
272 case Opt_uid:
273 opts->fs_uid = make_kuid(current_user_ns(), result.uint_32);
274 break;
275 case Opt_gid:
276 opts->fs_gid = make_kgid(current_user_ns(), result.uint_32);
277 break;
278 case Opt_umask:
279 opts->fs_fmask = result.uint_32;
280 opts->fs_dmask = result.uint_32;
281 break;
282 case Opt_dmask:
283 opts->fs_dmask = result.uint_32;
284 break;
285 case Opt_fmask:
286 opts->fs_fmask = result.uint_32;
287 break;
288 case Opt_allow_utime:
289 opts->allow_utime = result.uint_32 & 0022;
290 break;
291 case Opt_charset:
292 exfat_free_iocharset(sbi);
293 opts->iocharset = param->string;
294 param->string = NULL;
295 break;
296 case Opt_errors:
297 opts->errors = result.uint_32;
298 break;
299 case Opt_discard:
300 opts->discard = 1;
301 break;
302 case Opt_keep_last_dots:
303 opts->keep_last_dots = 1;
304 break;
305 case Opt_sys_tz:
306 opts->sys_tz = 1;
307 break;
308 case Opt_time_offset:
309 /*
310 * Make the limit 24 just in case someone invents something
311 * unusual.
312 */
313 if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60)
314 return -EINVAL;
315 opts->time_offset = result.int_32;
316 break;
317 case Opt_utf8:
318 case Opt_debug:
319 case Opt_namecase:
320 case Opt_codepage:
321 break;
322 default:
323 return -EINVAL;
324 }
325
326 return 0;
327 }
328
exfat_hash_init(struct super_block * sb)329 static void exfat_hash_init(struct super_block *sb)
330 {
331 struct exfat_sb_info *sbi = EXFAT_SB(sb);
332 int i;
333
334 spin_lock_init(&sbi->inode_hash_lock);
335 for (i = 0; i < EXFAT_HASH_SIZE; i++)
336 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
337 }
338
exfat_read_root(struct inode * inode)339 static int exfat_read_root(struct inode *inode)
340 {
341 struct super_block *sb = inode->i_sb;
342 struct exfat_sb_info *sbi = EXFAT_SB(sb);
343 struct exfat_inode_info *ei = EXFAT_I(inode);
344 struct exfat_chain cdir;
345 int num_subdirs, num_clu = 0;
346
347 exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
348 ei->entry = -1;
349 ei->start_clu = sbi->root_dir;
350 ei->flags = ALLOC_FAT_CHAIN;
351 ei->type = TYPE_DIR;
352 ei->version = 0;
353 ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
354 ei->hint_stat.eidx = 0;
355 ei->hint_stat.clu = sbi->root_dir;
356 ei->hint_femp.eidx = EXFAT_HINT_NONE;
357
358 exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
359 if (exfat_count_num_clusters(sb, &cdir, &num_clu))
360 return -EIO;
361 i_size_write(inode, num_clu << sbi->cluster_size_bits);
362
363 num_subdirs = exfat_count_dir_entries(sb, &cdir);
364 if (num_subdirs < 0)
365 return -EIO;
366 set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR);
367
368 inode->i_uid = sbi->options.fs_uid;
369 inode->i_gid = sbi->options.fs_gid;
370 inode_inc_iversion(inode);
371 inode->i_generation = 0;
372 inode->i_mode = exfat_make_mode(sbi, ATTR_SUBDIR, 0777);
373 inode->i_op = &exfat_dir_inode_operations;
374 inode->i_fop = &exfat_dir_operations;
375
376 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >>
377 inode->i_blkbits;
378 ei->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff;
379 ei->i_size_aligned = i_size_read(inode);
380 ei->i_size_ondisk = i_size_read(inode);
381
382 exfat_save_attr(inode, ATTR_SUBDIR);
383 inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
384 current_time(inode);
385 exfat_truncate_atime(&inode->i_atime);
386 return 0;
387 }
388
exfat_calibrate_blocksize(struct super_block * sb,int logical_sect)389 static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect)
390 {
391 struct exfat_sb_info *sbi = EXFAT_SB(sb);
392
393 if (!is_power_of_2(logical_sect)) {
394 exfat_err(sb, "bogus logical sector size %u", logical_sect);
395 return -EIO;
396 }
397
398 if (logical_sect < sb->s_blocksize) {
399 exfat_err(sb, "logical sector size too small for device (logical sector size = %u)",
400 logical_sect);
401 return -EIO;
402 }
403
404 if (logical_sect > sb->s_blocksize) {
405 brelse(sbi->boot_bh);
406 sbi->boot_bh = NULL;
407
408 if (!sb_set_blocksize(sb, logical_sect)) {
409 exfat_err(sb, "unable to set blocksize %u",
410 logical_sect);
411 return -EIO;
412 }
413 sbi->boot_bh = sb_bread(sb, 0);
414 if (!sbi->boot_bh) {
415 exfat_err(sb, "unable to read boot sector (logical sector size = %lu)",
416 sb->s_blocksize);
417 return -EIO;
418 }
419 }
420 return 0;
421 }
422
exfat_read_boot_sector(struct super_block * sb)423 static int exfat_read_boot_sector(struct super_block *sb)
424 {
425 struct boot_sector *p_boot;
426 struct exfat_sb_info *sbi = EXFAT_SB(sb);
427
428 /* set block size to read super block */
429 sb_min_blocksize(sb, 512);
430
431 /* read boot sector */
432 sbi->boot_bh = sb_bread(sb, 0);
433 if (!sbi->boot_bh) {
434 exfat_err(sb, "unable to read boot sector");
435 return -EIO;
436 }
437 p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
438
439 /* check the validity of BOOT */
440 if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) {
441 exfat_err(sb, "invalid boot record signature");
442 return -EINVAL;
443 }
444
445 if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) {
446 exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */
447 return -EINVAL;
448 }
449
450 /*
451 * must_be_zero field must be filled with zero to prevent mounting
452 * from FAT volume.
453 */
454 if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero)))
455 return -EINVAL;
456
457 if (p_boot->num_fats != 1 && p_boot->num_fats != 2) {
458 exfat_err(sb, "bogus number of FAT structure");
459 return -EINVAL;
460 }
461
462 /*
463 * sect_size_bits could be at least 9 and at most 12.
464 */
465 if (p_boot->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS ||
466 p_boot->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) {
467 exfat_err(sb, "bogus sector size bits : %u",
468 p_boot->sect_size_bits);
469 return -EINVAL;
470 }
471
472 /*
473 * sect_per_clus_bits could be at least 0 and at most 25 - sect_size_bits.
474 */
475 if (p_boot->sect_per_clus_bits > EXFAT_MAX_SECT_PER_CLUS_BITS(p_boot)) {
476 exfat_err(sb, "bogus sectors bits per cluster : %u",
477 p_boot->sect_per_clus_bits);
478 return -EINVAL;
479 }
480
481 sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits;
482 sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits;
483 sbi->cluster_size_bits = p_boot->sect_per_clus_bits +
484 p_boot->sect_size_bits;
485 sbi->cluster_size = 1 << sbi->cluster_size_bits;
486 sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length);
487 sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset);
488 sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset);
489 if (p_boot->num_fats == 2)
490 sbi->FAT2_start_sector += sbi->num_FAT_sectors;
491 sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset);
492 sbi->num_sectors = le64_to_cpu(p_boot->vol_length);
493 /* because the cluster index starts with 2 */
494 sbi->num_clusters = le32_to_cpu(p_boot->clu_count) +
495 EXFAT_RESERVED_CLUSTERS;
496
497 sbi->root_dir = le32_to_cpu(p_boot->root_cluster);
498 sbi->dentries_per_clu = 1 <<
499 (sbi->cluster_size_bits - DENTRY_SIZE_BITS);
500
501 sbi->vol_flags = le16_to_cpu(p_boot->vol_flags);
502 sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE);
503 sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
504 sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;
505
506 /* check consistencies */
507 if ((u64)sbi->num_FAT_sectors << p_boot->sect_size_bits <
508 (u64)sbi->num_clusters * 4) {
509 exfat_err(sb, "bogus fat length");
510 return -EINVAL;
511 }
512
513 if (sbi->data_start_sector <
514 (u64)sbi->FAT1_start_sector +
515 (u64)sbi->num_FAT_sectors * p_boot->num_fats) {
516 exfat_err(sb, "bogus data start sector");
517 return -EINVAL;
518 }
519
520 if (sbi->vol_flags & VOLUME_DIRTY)
521 exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
522 if (sbi->vol_flags & MEDIA_FAILURE)
523 exfat_warn(sb, "Medium has reported failures. Some data may be lost.");
524
525 /* exFAT file size is limited by a disk volume size */
526 sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
527 sbi->cluster_size_bits;
528
529 /* check logical sector size */
530 if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits))
531 return -EIO;
532
533 return 0;
534 }
535
exfat_verify_boot_region(struct super_block * sb)536 static int exfat_verify_boot_region(struct super_block *sb)
537 {
538 struct buffer_head *bh = NULL;
539 u32 chksum = 0;
540 __le32 *p_sig, *p_chksum;
541 int sn, i;
542
543 /* read boot sector sub-regions */
544 for (sn = 0; sn < 11; sn++) {
545 bh = sb_bread(sb, sn);
546 if (!bh)
547 return -EIO;
548
549 if (sn != 0 && sn <= 8) {
550 /* extended boot sector sub-regions */
551 p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4];
552 if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE)
553 exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x",
554 sn, le32_to_cpu(*p_sig));
555 }
556
557 chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize,
558 chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR);
559 brelse(bh);
560 }
561
562 /* boot checksum sub-regions */
563 bh = sb_bread(sb, sn);
564 if (!bh)
565 return -EIO;
566
567 for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) {
568 p_chksum = (__le32 *)&bh->b_data[i];
569 if (le32_to_cpu(*p_chksum) != chksum) {
570 exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)",
571 le32_to_cpu(*p_chksum), chksum);
572 brelse(bh);
573 return -EINVAL;
574 }
575 }
576 brelse(bh);
577 return 0;
578 }
579
580 /* mount the file system volume */
__exfat_fill_super(struct super_block * sb)581 static int __exfat_fill_super(struct super_block *sb)
582 {
583 int ret;
584 struct exfat_sb_info *sbi = EXFAT_SB(sb);
585
586 ret = exfat_read_boot_sector(sb);
587 if (ret) {
588 exfat_err(sb, "failed to read boot sector");
589 goto free_bh;
590 }
591
592 ret = exfat_verify_boot_region(sb);
593 if (ret) {
594 exfat_err(sb, "invalid boot region");
595 goto free_bh;
596 }
597
598 ret = exfat_create_upcase_table(sb);
599 if (ret) {
600 exfat_err(sb, "failed to load upcase table");
601 goto free_bh;
602 }
603
604 ret = exfat_load_bitmap(sb);
605 if (ret) {
606 exfat_err(sb, "failed to load alloc-bitmap");
607 goto free_upcase_table;
608 }
609
610 ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
611 if (ret) {
612 exfat_err(sb, "failed to scan clusters");
613 goto free_alloc_bitmap;
614 }
615
616 return 0;
617
618 free_alloc_bitmap:
619 exfat_free_bitmap(sbi);
620 free_upcase_table:
621 exfat_free_upcase_table(sbi);
622 free_bh:
623 brelse(sbi->boot_bh);
624 return ret;
625 }
626
exfat_fill_super(struct super_block * sb,struct fs_context * fc)627 static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
628 {
629 struct exfat_sb_info *sbi = sb->s_fs_info;
630 struct exfat_mount_options *opts = &sbi->options;
631 struct inode *root_inode;
632 int err;
633
634 if (opts->allow_utime == (unsigned short)-1)
635 opts->allow_utime = ~opts->fs_dmask & 0022;
636
637 if (opts->discard && !bdev_max_discard_sectors(sb->s_bdev)) {
638 exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard");
639 opts->discard = 0;
640 }
641
642 sb->s_flags |= SB_NODIRATIME;
643 sb->s_magic = EXFAT_SUPER_MAGIC;
644 sb->s_op = &exfat_sops;
645
646 sb->s_time_gran = 10 * NSEC_PER_MSEC;
647 sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
648 sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;
649
650 err = __exfat_fill_super(sb);
651 if (err) {
652 exfat_err(sb, "failed to recognize exfat type");
653 goto check_nls_io;
654 }
655
656 /* set up enough so that it can read an inode */
657 exfat_hash_init(sb);
658
659 if (!strcmp(sbi->options.iocharset, "utf8"))
660 opts->utf8 = 1;
661 else {
662 sbi->nls_io = load_nls(sbi->options.iocharset);
663 if (!sbi->nls_io) {
664 exfat_err(sb, "IO charset %s not found",
665 sbi->options.iocharset);
666 err = -EINVAL;
667 goto free_table;
668 }
669 }
670
671 if (sbi->options.utf8)
672 sb->s_d_op = &exfat_utf8_dentry_ops;
673 else
674 sb->s_d_op = &exfat_dentry_ops;
675
676 root_inode = new_inode(sb);
677 if (!root_inode) {
678 exfat_err(sb, "failed to allocate root inode");
679 err = -ENOMEM;
680 goto free_table;
681 }
682
683 root_inode->i_ino = EXFAT_ROOT_INO;
684 inode_set_iversion(root_inode, 1);
685 err = exfat_read_root(root_inode);
686 if (err) {
687 exfat_err(sb, "failed to initialize root inode");
688 goto put_inode;
689 }
690
691 exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos);
692 insert_inode_hash(root_inode);
693
694 sb->s_root = d_make_root(root_inode);
695 if (!sb->s_root) {
696 exfat_err(sb, "failed to get the root dentry");
697 err = -ENOMEM;
698 goto free_table;
699 }
700
701 return 0;
702
703 put_inode:
704 iput(root_inode);
705 sb->s_root = NULL;
706
707 free_table:
708 exfat_free_upcase_table(sbi);
709 exfat_free_bitmap(sbi);
710 brelse(sbi->boot_bh);
711
712 check_nls_io:
713 unload_nls(sbi->nls_io);
714 exfat_free_iocharset(sbi);
715 sb->s_fs_info = NULL;
716 kfree(sbi);
717 return err;
718 }
719
exfat_get_tree(struct fs_context * fc)720 static int exfat_get_tree(struct fs_context *fc)
721 {
722 return get_tree_bdev(fc, exfat_fill_super);
723 }
724
exfat_free(struct fs_context * fc)725 static void exfat_free(struct fs_context *fc)
726 {
727 struct exfat_sb_info *sbi = fc->s_fs_info;
728
729 if (sbi) {
730 exfat_free_iocharset(sbi);
731 kfree(sbi);
732 }
733 }
734
exfat_reconfigure(struct fs_context * fc)735 static int exfat_reconfigure(struct fs_context *fc)
736 {
737 fc->sb_flags |= SB_NODIRATIME;
738
739 /* volume flag will be updated in exfat_sync_fs */
740 sync_filesystem(fc->root->d_sb);
741 return 0;
742 }
743
744 static const struct fs_context_operations exfat_context_ops = {
745 .parse_param = exfat_parse_param,
746 .get_tree = exfat_get_tree,
747 .free = exfat_free,
748 .reconfigure = exfat_reconfigure,
749 };
750
exfat_init_fs_context(struct fs_context * fc)751 static int exfat_init_fs_context(struct fs_context *fc)
752 {
753 struct exfat_sb_info *sbi;
754
755 sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL);
756 if (!sbi)
757 return -ENOMEM;
758
759 mutex_init(&sbi->s_lock);
760 mutex_init(&sbi->bitmap_lock);
761 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
762 DEFAULT_RATELIMIT_BURST);
763
764 sbi->options.fs_uid = current_uid();
765 sbi->options.fs_gid = current_gid();
766 sbi->options.fs_fmask = current->fs->umask;
767 sbi->options.fs_dmask = current->fs->umask;
768 sbi->options.allow_utime = -1;
769 sbi->options.iocharset = exfat_default_iocharset;
770 sbi->options.errors = EXFAT_ERRORS_RO;
771
772 fc->s_fs_info = sbi;
773 fc->ops = &exfat_context_ops;
774 return 0;
775 }
776
777 static struct file_system_type exfat_fs_type = {
778 .owner = THIS_MODULE,
779 .name = "exfat",
780 .init_fs_context = exfat_init_fs_context,
781 .parameters = exfat_parameters,
782 .kill_sb = kill_block_super,
783 .fs_flags = FS_REQUIRES_DEV,
784 };
785
exfat_inode_init_once(void * foo)786 static void exfat_inode_init_once(void *foo)
787 {
788 struct exfat_inode_info *ei = (struct exfat_inode_info *)foo;
789
790 spin_lock_init(&ei->cache_lru_lock);
791 ei->nr_caches = 0;
792 ei->cache_valid_id = EXFAT_CACHE_VALID + 1;
793 INIT_LIST_HEAD(&ei->cache_lru);
794 INIT_HLIST_NODE(&ei->i_hash_fat);
795 inode_init_once(&ei->vfs_inode);
796 }
797
init_exfat_fs(void)798 static int __init init_exfat_fs(void)
799 {
800 int err;
801
802 err = exfat_cache_init();
803 if (err)
804 return err;
805
806 exfat_inode_cachep = kmem_cache_create("exfat_inode_cache",
807 sizeof(struct exfat_inode_info),
808 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
809 exfat_inode_init_once);
810 if (!exfat_inode_cachep) {
811 err = -ENOMEM;
812 goto shutdown_cache;
813 }
814
815 err = register_filesystem(&exfat_fs_type);
816 if (err)
817 goto destroy_cache;
818
819 return 0;
820
821 destroy_cache:
822 kmem_cache_destroy(exfat_inode_cachep);
823 shutdown_cache:
824 exfat_cache_shutdown();
825 return err;
826 }
827
exit_exfat_fs(void)828 static void __exit exit_exfat_fs(void)
829 {
830 /*
831 * Make sure all delayed rcu free inodes are flushed before we
832 * destroy cache.
833 */
834 rcu_barrier();
835 kmem_cache_destroy(exfat_inode_cachep);
836 unregister_filesystem(&exfat_fs_type);
837 exfat_cache_shutdown();
838 }
839
840 module_init(init_exfat_fs);
841 module_exit(exit_exfat_fs);
842
843 MODULE_ALIAS_FS("exfat");
844 MODULE_LICENSE("GPL");
845 MODULE_DESCRIPTION("exFAT filesystem support");
846 MODULE_AUTHOR("Samsung Electronics Co., Ltd.");
847